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Author Topic: sound city clean-up  (Read 17006 times)

ilyaa

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Re: sound city clean-up
« Reply #15 on: March 15, 2014, 06:18:06 PM »
can you download/open this file:

https://drive.google.com/file/d/0B96d2ZNKqmsHWUljZG1wU1ROT0E/edit?usp=sharing

?

if not ill upload them a different way (easiest this way but you know......lazy way isnt the only way....)

DrGonz78

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Re: sound city clean-up
« Reply #16 on: March 16, 2014, 02:32:40 AM »
That file is not working either... I was able to download some of the files the other day, but now they won't download. I logged into a gmail account and downloaded a couple. Now it won't download at all... If you have gmail account you can still view the pics but downloading is hit or miss, mostly miss. Try dropcanvas it rocks!!
“A person who never made a mistake never tried anything new.” -Albert Einstein

ilyaa

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Re: sound city clean-up
« Reply #17 on: March 16, 2014, 03:44:37 AM »
jesus what a simple solution to such a pain in everyones....

http://dropcanvas.com/nl0yl

thanks, Gonz!!

(i edited my previous post with the correct corresponding file titles)

DrGonz78

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Re: sound city clean-up
« Reply #18 on: March 16, 2014, 07:15:26 AM »
So yeah that mains power selector switch is totally missing the switch part huh? I have attached a version of the PT that someone drew out, pretty sure this might help. The orange wire tap should be the 115v or 105v on this diagram. Confusing part there is I see red and yellow taps but where does that orange wire in the middle go? The whole switch is wired up in a manner that makes no sense to me.

Man this thing is so confusing! All the close up pics are nice but a fuller picture will help see how all the wiring is connected. Honestly all the AC wiring in the amp needs to be redone and I am pretty sure you are already starting that task. Others here will definitely know more than I will, good luck!  :tu:
« Last Edit: March 16, 2014, 07:21:02 AM by DrGonz78 »
“A person who never made a mistake never tried anything new.” -Albert Einstein

g1

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Re: sound city clean-up
« Reply #19 on: March 16, 2014, 08:31:41 PM »
  The voltage selector is a 2 piece switch, like the old style Marshall switches.  The piece you are missing looks like this:
http://www.mojotone.com/amp-parts?search=Switches+Marshall+Old+Style+Impedance+Selector+Switch
http://www.amplifiedparts.com/products/P-H502
  It will be very easy to bypass, but as Dr.Gonz stated, you need to post some pictures where we can see everything at once, not just little bits at a time.

ilyaa

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Re: sound city clean-up
« Reply #20 on: March 16, 2014, 09:53:40 PM »
http://dropcanvas.com/#oykJ406u48IJ9y

those work okay?

EDIT: this link works now - fixed it
« Last Edit: March 17, 2014, 11:57:21 AM by ilyaa »

ilyaa

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Re: sound city clean-up
« Reply #21 on: March 17, 2014, 12:17:07 AM »
ohhhh

now i see! i thought that switch ddint make sense.....i thought it was an internal thing - of course its not working!! i wonder if it's always been missing that part........

alright ill just hard wire for 115V, then! let me know if you guys see anything the pix i should take note of....and whats the best way to hard wire it??

Roly

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Re: sound city clean-up
« Reply #22 on: March 17, 2014, 02:48:56 AM »
  The voltage selector is a 2 piece switch, like the old style Marshall switches.  The piece you are missing looks like this:
http://www.mojotone.com/amp-parts?search=Switches+Marshall+Old+Style+Impedance+Selector+Switch
http://www.amplifiedparts.com/products/P-H502
  It will be very easy to bypass, but as Dr.Gonz stated, you need to post some pictures where we can see everything at once, not just little bits at a time.

Oh that non-captive thing.  They are always falling out and getting lost.  Generally bad idea.
If you say theory and practice don't agree you haven't applied enough theory.

ilyaa

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Re: sound city clean-up
« Reply #23 on: March 21, 2014, 02:02:15 AM »
check it out:

ran into someone with a perfect condition sound city concord combo!

he let me take some pix (i couldnt take it fully apart and kind of had to rush....) but heres what i got:

http://dropcanvas.com/#Mw8P8TI4N7mKe4

what i saw and gonz' picture dont quite jive....

it seems like the fat yellow wire going into the PT is the 115V tap (seeing as thats the way both my amp and the working one are wired). there are no orange wires going into the PT. the only orange wires are the ones around the mains fuse. also, doesnt it seem like the red wire is the bottom, rather than the top of the primaryy, seeing as its also connected to green/yellow (safety)?

in the absence of a working selector, how can i hard-wire it?
« Last Edit: March 21, 2014, 02:35:50 AM by ilyaa »

g1

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Re: sound city clean-up
« Reply #24 on: March 21, 2014, 11:21:36 AM »
  Sorry I can not look at 100's of megs worth of pictures as I don't have unlimited high speed internet.
  If you are unable to read schematics you should not be doing this.
If you are able, then you should be able to follow the drawing.
Try to tell us exactly where wires are going, rather than telling what colors, the color scheme of this wiring is horrible.
  If the yellow of the PT primary is the 115V tap, then you want to connect the "out" of the fuse holder directly to the 115V tap, bypassing the voltage selector.

The only wire on the PT primary that should go to chassis is the core/case wire.  Look on the schematic at the middle of the PT, at the bottom it shows a wire going over to chassis ground.  Is the green/yellow (safety) you mentioned connected to chassis? 
Disconnect the red wire and measure the resistance to the case of the PT, does it measure as a short (0 ohms) ?

g1

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Re: sound city clean-up
« Reply #25 on: March 21, 2014, 02:04:44 PM »
  Looking a bit more, one of the taps connected to the voltage selector should also go to the pilot light.  Is that where the grn/yellow connected to the red is going?  I think the red is the 245V tap and the grn/yl it connects to should go to the pilot lamp.

Do not trust any wire colors, someone has rewired this amp using AC cord.  Does the 3rd prong on the AC plug (round pin) connect to a wire that goes to the chassis?

DrGonz78

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Re: sound city clean-up
« Reply #26 on: March 22, 2014, 03:01:22 AM »
Strange thing about these amps is that I am starting to think the AC cord wiring is how they were made...

http://www.chambonino.com/work/soundcity/city3.html

http://www.chambonino.com/work/soundcity/city7.html

I would bet that green/yel wire that connects to the RED 245v tap is going to one side of the pilot lamp.
“A person who never made a mistake never tried anything new.” -Albert Einstein

Roly

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Re: sound city clean-up
« Reply #27 on: March 22, 2014, 09:08:22 AM »
Quote from: DrGonz78
...green/yel wire that connects to the RED...

AAAARRRGGGhhhhh ... {I feel ill}   :duh
If you say theory and practice don't agree you haven't applied enough theory.

phatt

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Re: sound city clean-up
« Reply #28 on: March 23, 2014, 07:12:15 AM »
I once worked on a really old open backed Amp which had exposed mains terminals right behind the upper rear panel board.

The handle was long gone so I bent down to lift the Amp onto bench and felt the terminals of what was the transformer lugs (mains side).  :o Sent shivers down my spine, Thank God it was unplugged at the time.

If I recall twas a Roland GA50 or something like that. :-X
There is some scary stuff out there so wise to take extra care no matter how big and pro the brand name plate looks.  8)
Phil.

Roly

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Re: sound city clean-up
« Reply #29 on: March 23, 2014, 10:18:19 AM »
I've managed to do something like that when it wasn't unplugged (or switched off at the outlet).  :o  Fa-zat! - eee-haaa   xP
If you say theory and practice don't agree you haven't applied enough theory.

 

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